The present invention relates to swimming flippers, and in particular to a flipper substantially consisting of a blade and a shoe or footwear suitably shaped and provided with a sole.
It is known that while swimming the scuba diver substantially makes with each flipper, synchronously and continuously, two kinds of movement or flipping: a movement down-up, i.e. the active flipping, and a movement up-down, i.e. the passive flipping. During the passive flipping the back of the blade acts onto the water mass below, whereas in the active flipping the lower surface of the blade acts onto the water mass in order to ensure the necessary forward thrust for the scuba diver. It is known about the existence of flippers provided with blades which can be rotated of a certain angle with respect to the sole, and which are connected to front protruding elements of said sole by means of side extensible elements, which, during the passive flipping, stretch out and allow to vary the inclination of the blade with respect to the shoe and to the sole under the action of the water acting onto the back of said blade, so as to ease the diver's movement. During the active flipping said extensible elements shrink back to the rest position and substantially allow the blade to line up with the sole surface, thus allowing the flipper to be in an optimal position and with a wide thrust surface on the water mass in touch with the lower surface of the blade. Such flippers, however, because of said blades rotating of a certain angle with respect to the shoe and its sole, require the mounting of side stroke ends used by the blade at the end of the active flipping, so as to avoid undesired rotations upwards. The mounting of said stroke ends makes the blade rather difficult to carry out, and the side extensible elements, besides being difficult to remove and replace, do not always allow a perfect elasticity and flexibility of the blade.
The present invention aims at carrying out a swimming flipper which overcomes the disadvantages of known flippers, which is easy to carry out and ensures a high efficiency during the diver's active and passive flipping.
Said aim is achieved by the present invention by means of a swimming flipper consisting of a footwear or shoe equipped with a sole provided on its front and lateral sides with at least two protruding elements, and a blade connected to said sole; said flipper consists of at least an extensible element substantially transversal with respect to the blade and laterally connected to said protruding elements and centrally to the flipper surface in an area between said protruding elements.
According to an aspect of the present invention, the extensible element consists of at least two lateral portions, whose ends are connected to the protruding elements, and of at least a central portion connected to the blade surface by means of suitable seats obtained on said surface. The lateral portions of said connecting rod can be regarded, during the active flipping, as abutting or limit elements of the stroke in the opposite direction for the upper surface of the blade, advantageously avoiding the mounting of stroke ends.
Moreover, according to another aspect of the present invention, it is possible, thanks to the mounting of the transversal extensible element, to carry out a flipper in which the blade is connected to the shoe sole by means allowing its removal, if necessary.